The leather worker was a worker by caste ,hence his skills with needle should be great and should have the natural ability to use the needle at a very fast pace. Along with that he has to help in a Festival as well as attend to his wife’s labor. The Sun was also setting, which means he had to complete his work before the natural light goes off(no electricity those days!). All these events would have pressurized the leather worker to work at a frantic pace i.e use his needle at a very very high speed. The poet uses this hyperbolic metaphor to compare the speed of the King in war.